I don't see a problem with the penalty. It has taught me most of my driving skills and has teached me to be a little more cautious and to pay attention to the AI's line and to stay away from them. The penalty, in my opinion, was meant to be a teaching tool. I think it was added to teach the user how to be a better driver without making stupid moves like using the AI's cars as a way of getting around that tight turn or using the wall to turn the car on the dirt/snow tracks when the car is not responding properly.
However, I do agree that getting the penalty when you get hit was a bit much, but I think it's fair when you get the penalty when you hit the wall or another car. In reality when you hit another car, whats the penalty? You loose your license, depending on what country you live in, or get it suspended and can get a ticket or what ever the law is in your country. Yet, I feel it makes perfect sense to have the penalty. Whats the point of palying a true to life racing game when all you do is hit the AI just to get around a hair pin or use the wall to get around the tight turns on the rally tracks? All those gamers who are not new to the GT series would agree with me on one point, hitting the AI or using the wall to get around the tight turns is just plain foolish. If you drive like that, then I believe you deserve the penalty.
All in all, the penalty I feel was meant as a teaching tool and wasn't meant to "pull your hair out".
Either than that, the game is very enjoyable, and has and always will be the number racing game in my book.